Gun control compensating mechanism



Dec. 28 1948. w H 2,457,532

GUN CONTROL COMPENSATING MECHANISM Filed June 20, 1945 INVENTOR: FREDERICK W. CUNNINGHAM Ya Hi5 ATTORNEYS.

Patented Dec. 28, 1948 GUNooNTRoL penetrate-ewe MECHANISM a or to Arma l/Yllq irr ml iaiizf r l I Corporation, Brooklyn, N. Y.', a

corijdratioii'of New York Application June 20, rszisg'seriai no'eoois'sv 2'Claiins.

Thisinvention-relates to gun control mechanism, and has particular reference to mechanism forborredting the-movementof; guns, although theinvention is not limited't'o that use. w

'- "Guns of the class having-the nut and screw -.'type of' elevatingmechanism, which includesmany r guns of suchia-rge size-'and'weight as torequire it; have a non-linear-elevation characteristic due to-the changeinthe effective era-n1; arm with "change of the elevationangle'and the accompanying distortion of the geardrive; As the result, the gun elevating-motorlinearlyiollowsthe elevation of a director or'cal'culator dummy gun; for ex- "--'amp1e,-but the gun itself-does not,- and consequently serious'errorsin gun elevation occur.

accordance with the present invention, a 'correctingmechanismj-isprovided for automatically compensating for thechangein the effective crank arm and accompanyinggear drive distor- 'tionof --t-he 1 nut and -scrw"=*type of elevating mechanism, so that the desired linear elevation characteristics of thegunareobtained and accurate elevation angle-follow up results.

The preferred embodiment-of the invention includes a cam shaped to correct the non-linear;

error and actuated in'accordancwith the elevation movements of the gun for correspondingly a'djusting'the angular 'i'el'ationbetweeri the "stator f a'nd the rotor of an elevation-angle signal-receiv'ing' control transformer, "-"whose 'co'r're'cted rotor secondary winding voltages are 'a'mplified and impressedon the gun elevating motor, which drives the g'un'"tlfro u gh' the o'pertransmitted "Elevation" angle and then d ergizes "itself by rotating the transformer rotor to' aim i'nd uc'cive or null position.

It will be seen that the operation characteristic of a nut and screw type gun elevation mechanism is rendered linear and therefore accurate in a simple and reliable manner with the control correcting mechanism of this invention, further details of which will be apparent upon examination of the accompanying drawings, in which:

Figure 1 is a perspective view of a gun provided with a corrected nut and screw type elevating mechanism in accordance with the present invention; and

Fig. 2 is a schematic and wiring diagram of the control mechanism thereof.

Referring to Fig. 1 of the drawings, numeral designates a gun mounted for angular motion in elevation about trunnions H on a mount 12 sup-- ported on the deck of a ship, for example. Gun II] is elevated by the common nut and screw mechanism, including the screw l3 non-rotatably ;;pivot ed atitsupper endon the barrel of the gun -10; and passing through-a nut l d. Nut ll is l' -rotatablyfmounted on ajthrust bearing 5 carried -br a'yo' el 5 p votedont he m unt! ziorqs i l 5- "tion about the axisj'ofdrive bevel, gear lit meshing with bevel-gear I 4fon .jnut l4 Eleyation. drive e gear-I11. t v m d enzelerau n' haft. rfjournalledion themount jl 2 anddriyenpy eleva- 'iionmotflr i 1thr re p nbe ri 1 L show 10 Referringparticularly to; Eig 2. the elevation an l a om t directo iorral u tcr pre d 1 m na s .zltfa i pp ied. hr u f x le? leads: .2 to t e three-phase. windin 22 ref e a r 79 aft e i-sye hron s .gqnt

i't nsformerjor ei e '59 a WTP IQF meta h n i fieldi si he le..w. nsl n rete l: 23

." find di w etie amnlii ed' aa g tte tiona r e qn am fier 2.4-) 1 g 20ielevati'ng mo o 25.; c nnected y. ea tirs which accordingly advances qr retracts screw l3 *toraise-orlowergunflfl in elevation.

The gun elevation shaft 'lfi, so;driven;by motor 5 25, is connected to rotor 23 and by shafting 26 to a'cam -28 whose I0119WI129-is held in contact therewithbyspiingflfl. "As follower 2.) is actuated by cam'i28"'itf2advan-cesor retracts; a; rack 3, I to rotate pinion*32; whichis connected by gearing 33"to"the' stator "21*of ithecontrol transformer so that the' angular relation"between-ithe' stator Twinding' '22""and;"rot'0r"winding 23'isadjusted.

Theadjustment"of'stator 2'l'is Such'asto correct "tl'le tion -rectilinear charateristics of :the" nut'and "scr"ewelevatingmecnanism'andcam 2a 'isshaped accordingly.

' In the preferred embodiment shown in Fig. 1, the cam 28 is mounted directly on the shaft 34 carrying the rotor Winding 23 and this shaft is connected by worm and wheel combination 35, shaft 36 and bevel gears 31 to elevation shaft I8, 50 that the cam 28 is actuated directly in accordance with the movements of gun II) in elevation.

In operation of the nut and screw gun elevating mechanism shown in Fig. 1, elevation of the gun 10 causes screw l3 to swing counter-clockwise, which in turn causes yoke I 6 to swing in the same direction about the axis of elevation shaft 18, thus changing the relation between the motion of elevation shaft [8 and the motion of gun Ill. The same but reverse incorrect movement results when the gun ID is depressed. The exact amount of incorrection can be readily determined for every degree of elevation of the gun l0 and these incorrections plotted to serve as a basis for laying out the contour of cam 28. Although cam 28 is rotated angularly in step with the angular movement of the gun II], the cam rotates slightly less than one complete revolution during the full elevation and depression movement range of the As cam 28 .rotates, its follower 29 displaces rack 3!, which, through meshing pinion 32 and gears 33, rotates stator 21 of the receiver or control transformer to accordingly distort the signal impressed on winding 22, so that the motordriving voltage induced in rotor 23 causes the motor 25 to elevate gun It! .more or less in the prescribed correction range than theoriginal signal required, thus compensating for the nonlinear gun elevation characteristic of the nut and screw mechanism l3, I4. This greateror less elevation rotation of elevator motor 25 is directly dependent upon the angle through which rotor coil 23 is driven by motor 25 the non-inductive null or motor deenergizing position. Thus if stator 21 is "rotated by cam 28 in one direction, rotor coil 23 must be driven through a greater angle to null'position, and vice versa.

It will be understood that the invention is also applicable to other driving mechanisms where the driven member is to follow a course Or have a movement difierent than that dictated by the construction of the intervening gearing or other driving mechanism, and that cam 28 may be shaped to introduce other corrections simultaneously with or in addition to the aforementioned elevation corrections, such as corrections for gun erosion, parallax, and the like. Such corrections may be introduced by the present mechanism, even where the gun elevation mechanism has linear characteristics as in the case'of a gear sector on the gun having its pitch center about the trunnion axes and driven by a pinion.

Although a preferred embodiment of the invention has been illustrated and described herein, the invention is not limited thereby, but is susceptibleof changes in form and detail within the scope of the appended claims.

I claim:

1. In combination with a motor-driven nut and screw mechanism for driving a member about a pivot, means for correcting the inherent non-linear characteristics of said mechanism including a cam having a contour conforming to the difierence between the inherent non-linear drive pattern of said mechanism and the desired linear pattern, driving connections between said mechanism and said cam, a control transformer having a rotatable rotor and a rotatable stator,

a source of signal voltage for energizing said mechanism, electrical connections between said source and said stator, electrical connections between said rotor and said motor, driving connections between said motor and said rotor for rotating the latter to non-inductive angular relation with said stator, and driving connections between said cam and said stator for rotating the latter to thereby change the angle through which the rotor is driven by said motor for accordingly correcting the movement of said member.

2. In combination with a motor-driven nut and screw mechanism for elevating a gun, means for correcting the inherent non-linear characteristics of said mechanism including a cam having a'contour conforming to the difference between the inherent non-linear drive pattern of said mechanism and the desired linear pattern, driving connections between said motor and said cam, a control transformer having a rotatable rotor and a rotatable stator, a source of varying elevation angle signal voltagefor energizing said mechanism, electrical connections between said source and said stator, electrical connections between said rotor and said motor for energizing said motor in accordance with the signal voltage induced in said rotor, an amplifier in said connections between said rotor and said motor, driving connections between said motor and said rotor for rotating the latter to non-inductive angular relation with said stator, and driving connections between said cam and said stator for rotating the latter to thereby change the angle through which the rotor is driven by said motor for accordingly correcting the movement of said gun to conform to the'elevation angle signal.

FREDERICK W. CUNNINGHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,684,132 Hewlett et al Sept. 11, 1928 1,684,133 Nixdorf Sept. 11, 1928 2,336,994 MacKay Dec. 14, 1933 2,412,356 Roberts et al. Dec. 10, 1946 OTHER REFERENCES U. S. Navy Synchros-Ordnance Pamphlet No. 1303, December 15, 19 14, page 114. 

